Training to failure is a topic that is currently being consistently presented and discussed amongst the knowledge sources that I frequent. I have always enjoyed what I considered to be ‘pushing myself’ although I never quantified it in any way. I came to weight lifting very recently, really just as I was beginning my current master’s program in exercise science. I began following a number of expert individuals, reading books and research studies, and listening to podcasts in an effort to educate myself. I am still extraordinarily new to this realm and really don’t have any clue yet how to parse this information. Taking advantage of this space to catalog my thoughts and to iterate my practices, using myself as my n = 1, seems like a reasonable starting point!
I probably don’t need to explain what training to failure indicates, but training to failure, or more accurately momentary muscular failure, is simply performing repetitions until you can no longer do so without severely compromising form. My understanding is that the traditional view supports this practice, indicating that training to momentary muscular failure induces the greatest adaptations to the muscle tissue and neuromuscular system. However, recent research is elucidating further nuance in regards to when and why to pursue muscular failure, and that less may be actually more in this context (1).
Given my sub-rudimentary grasp of the topic, I am going to focus on just this one study for the time being and highlight a few things that stood out to me. Hopefully, in time, I will be much better equipped to dive into the why behind the observations. I really liked a few specific aspects of this study, one being how well the authors described the outcomes and their potential implications (1). I really found it very accessible, approachable, and eye-opening, and cannot express how much I appreciated the sharing of their expert viewpoints for us newbies.
First things first. This study involved twenty-four men and women, evenly split amongst the sexes, with previous lifting experience (1). Each participant engaged in all three protocols of six sets of the barbell bench press with a load of 75% of their 1-repetition maximum to either failure, 1 repetition from failure, or three repetitions from failure. A one-repetition maximum is tested by adding weight until only one repetition can be performed. This is assessed prior to the start of a study or intervention. Both neuromuscular fatigue and recovery were the primary outcomes being measured (1). In a nutshell, what they discovered was that going to failure leads to more fatigue and a slower recovery, which is not entirely surprising even to the lay-person.
Now let’s dig into the juicy part. Let’s start with a couple of notes. Simply put, our muscles are composed of both type I and type II muscle fibers. Type I fibers tend to be more endurance based, generating lower forces for the sake of efficiency. Type II fibers excel at the opposite, generating rapid and forceful contractions for power. It has been established that performing a contraction to momentary muscular failure calls type II muscle fibers to action, even at low velocities, and their higher force production serves to drive robust adaptations (1). This is known as the size principle, whereby smaller fibers with lower energy demands (i.e. type I fibers) are the first to initiate contraction up until a given force is required, at which point larger, more powerful type II fibers enter the scene.
However, in spite of the adaptations induced by failure training, neuromuscular fatigue rises in conjunction and may exacerbate recovery, leading to a diminished volume of training and subsequent strength development (1). Toeing this balance is the art of an excellent personal trainer. As mentioned previously, the closer participants exercised to failure, the more fatigue they experienced and thus the longer their recovery. Nevertheless, after 24-hours, nearly all participants were fully recovered, demonstrated by complete resolution of neuromuscular function. When subjects left three repetitions in the tank, a slight ‘supercompensation’ was observed at 24-hrs post-exercise, meaning that lifting velocity actually improved beyond where it was initially. This is pretty cool and suggests that we might, if we’re super lucky, even get a little priming boost in this specific case.
The other point that prompted a raised eyebrow whilst reading was the impact of each protocol on training volume (1). While training to failure correlated with the largest number of repetitions being performed in the first set, overall using a three-reps-in-reserve protocol allowed for the most extensive training volume. As training volume is a critical determinant of adaptation, whether that be strength, hypertrophy, etc, this is a crucial takeaway. If stopping just shy of failure allows you to train more often and perform more total volume, this may help you achieve your goals to a greater extent than always going to failure. It is also worth noting how training to failure impacts your other training, especially of exercises using the same muscle group (1). Your performance will certainly decline if you train to failure in one exercise and subsequently engage in another exercise of the same muscle group. A good practice is thereby to arrange your exercises in order to maximize performance on what you value most.
Of course, there are countless ‘ifs’ and ‘buts’ and ‘it depends’ here. You can’t take one study, especially of 24 subjects, and let it inform all of your training practices. There are training differences, sex differences, and individual differences that cannot be ignored. How you respond to training will absolutely not mirror how these folks responded to this protocol. It’s just a tool like any other that’s worth exploring, learning to implement, and feeling free to toss aside if it doesn’t work for your task. A couple of things I want to keep in mind from this: 1) You don’t have to train to failure, especially not every session, to see performance gains, 2) Training to failure can compromise your performance on other exercises, so prioritize accordingly and place your heavy hitters early on in your session, 3) It’s probably worth incorporating some failure training along with some training that leaves fuel in the tank to cover all of your bases, 4) You can keep things spicy and engaging my alternating the goal of the workout and changing load and volume based on the objective, 5) If you do train to failure, keep in mind that your recovery will need to be more extensive. Program accordingly in the following sessions, or strategically place your train-to-failure day before your longest rest period.
References
- Refalo MC, Helms ER, Hamilton DL, Fyfe JJ. Influence of Resistance Training Proximity-to-Failure, Determined by Repetitions-in-Reserve, on Neuromuscular Fatigue in Resistance-Trained Males and Females. Sports Med Open. 2023;9(1):10. Published 2023 Feb 8. doi:10.1186/s40798-023-00554-y